Crankshaft grinding machine



J1me 3- R. A. COLE ET AL ,3 7

CRANKSHAFT GRINDING MACHINE Filed July 15, 1941 4 Sheets-Sheet l RAYMONDA. [301.5

FRANKLIN E. JOHNSON 9M LbEd-Zm alum ma June 22, 1943. R. A. COLE ET ALCRANKSHAFT GRINDING MACHINE Filed July 15, 1941 4 Sheets-Sheet 2 .m E 9N,lll. u M 7 fl m $6 HHH H H HHHHH HMHHHI l l l l l lnv Q n M mm I IH NHRAYMUND A. DULE F RA NKL IN E. JUHNSCIN June 22, 1943- R. A. COLE ET ALCRANKSHAFT GRINDING MACHINE Filed July 15, 1941 4 Sheets-Sheet 3 uwimmuzE L D a WE WWW X N M IJUHNSUN June 22, 1943. R. A. COLE ET AL CRANKSHAFTGRINDING MACHINE Filed July 15, 1941 4 Sheets-Sheet 4 3mm RAYMOND A.COLE FRANKLIN E.'. .JUHNSUN ulw M Patented June 22, 1943 Y UNITED STATESPATIENT OFFICE oalmxsnm GRINDING momma Raymond A. Cole and Franklin E.Johnson, Worcester, Mala, assignors to Norton Company, Worcester, Masa,a corporation of Massachusetts Application July 15, 1941, Serial No.402,468 1:01am. (01. 51-3) The. invention relates to grinding machines,and more particularly to amachine for grinding the crankpins of anautomotive crankshaft.

One object of the invention is to provide a simple and thoroughlypractical, readily controllable crankpin grinding machine. Anotherobject of the invention is to provide a crankpin grinding machine havinga multiplicity of grinding wheels which are arranged simultaneously togrind spaced aligned crankpins on a crankshaft. Another object of theinvention is to'provide a multiple wheel crankpin grinding machine witha hydraulically operated control mechanism whereby a plurality ofgrinding wheels may be indexed longitudinally and fed transverselysimultaneously to grind a plurality of pins ona crankshaft. v v

A further object of the inventionis to provide a fluid pressureinterlock between the wheel feed control and the wheel indexing ortraversing mechanism whereby the wheels cannot be indexed longitudinallyuntil the grinding wheels are in their rearward or inoperative position.A further object of the invention is to provide such a hydraulicinterlock which is operative to actuate a switchto stop the workrotation during the longitudinal traversing or indexing movement Theinvention accordingly consists in the features of construction,combinations of elements,

Fig.- 3 is a hydraulic diagrammatic illustration;

of a portion of the fluid pressure system, showing the traversingmechanism for the wheel slides:

the manually operable wheel feed adjusting mechanism; Fig. 6 is afragmentary rear elevation, on an enlarged scale of the hydraulicinterlock mechanism;

Fig. 7 is a fragmentary horizontal sectional view, taken approximatelyon the line 1-4 of Fig. 1, through the vertically movable steadyrest;

Fig. 8 is a fragmentary sectional view, on an enlarged scale takenapproximately on theline 8-3 of Fig. '1, through the control lever;

Fig. 9 is a fragmentary cross sectional view, on an enlarged scale,taken approximately on the line 3l of Fig. 4, through one of the controlvalves;

Fig. 10 is a diagrammatic illustration of a modified hydraulic system inwhich a single piston and cylinder mechanism serves simultaneously toindex two spaced grinding wheels; and

Fig. 114s a fragmentary cross sectional view,

taken approximately on the line il--li of Fig. 10.

A double head crankpin grindingmachine has been illustrated in thedrawings comprising a base 23 which serves as a support for a pair ofspaced transversely movable wheel slides 2i and 22 carrying grindingswheels and 2|, respecof the grinding wheels. Other objects will be inpart obvious or in part pointed out hereinafter.

tively. The grinding wheels 23 and 24 are supported on wheel spindles 25(only one of which has been shown in Fig. 2 of the drawings). The

wheel spindles 25 are Journalledin suitable bearings in the wheel slides2| and 22, respectively.

The wheelslide II is supported by a V-way 26 and a'flat way 21 and thewheel slide 22 is supported by a V-way2l and a flat way 29 so that theymay be fed transversely to produce the desired grinding action. l

The grinding wheels 23, and 2 together with their supporting wheelslides 2| and 22 are preferably arranged so that they may be indexed orFig. 4 is a combined electric wiring diagram Y and fragmentary hydraulicdiagram, showing the work stop control mechanism together with thegrinding wheel indexing and feeding mechanism the steady-rest actuatingmechanism;

' 5 is a fragmentary sectional view, taken approximately on the line Hof Fig. 2, through traversed longitudinally successively to position thegrinding wheels in operative positions to grind successive pairs ofaligned crankpins on a crankshaft 3| to be ground. As shown in Fig. 1,the grinding wheels 23 and 24 are positioned and arranged to grind apair of aligned crankpins Iland 32 on the crankshaft 30. After the pins3| and 32 have been ground to the required and predetermined size, thecrankshaft 30 is rotarily indexed to position a pair of pins'33 and 34in alignment so that the crankshaft 33 rotates about the axis of thepins 33 and 34, after which the grinding wheels 23 and 24 together withtheir supporting slides 2| and 22, respectively, are slmultaneouslyindexed toward each other into operative position in alignment with .thesecond pair of pins 33 and 34 to grind the same to the required andpredetermined size. Similarly,

after the pins 33 and 34 have been ground, the.

crankshaft 30 is again rotarily indexed to position the crankshaft sothat it rotates about the axis of a pair of aligned pins 33 and 33. Thewheels 23 and 24 together with their supporting slides 2| and 22 arethen again indexed toward each other into alignment with the pins "and36 so that these pins may be ground to the desired and predeterminedsize.

In order to provide for a longitudinal indexing of the grinding wheels23 and 24, the wheel slides 2| and 22 are mounted on longitudinallytraversable slides or carriages 31 and 33. respectively. The V-way 23and flat way 21 on the slide 2| mate with correspondingly shaped ways onthe upper surface of the longitudinally movable slide 31. Similarly, theV-way 23 and flat way 23 on the wheel slide 22 mate with correspondinglyshaped ways oh the upper surface of the longitudinally movable slide 33.The longitudinally movable slide 33 is supported by a V-way 331 and aflat way 40 on correspondingly shaped ways formed on the upper surfaceof the base 23 so that the slide 33 together with the wheel slide 22 andthe grinding wheel 24 may be indexed or traversed longitudinally toposition the grinding wheel 24 in the desired relationship with theportions of the work piece to be ground. The longitudinally movableslide 31 is similarly provided with a v-way and flat wayfnot shown)which correspond to the V-way 33 and' flat way 43, by means of which theslide 31 togetherwith the wheel slide 2| and the grinding wheel 23 maybe indexed or traversed longitudinally to position the grinding wheel 23in the desired and predetermined relationship with portions piece 30 tobe ground.

Grinding wheel drive corresponding multiple V-groove pulleys 43 and 49(only one of which is shown in Fig. 2) which are mounted on the outerends of the wheel spindles 25. The electricmotors 42 and 43 are startedand stopped by push button switches 13 and 14, respectively. v

A fluid pressure wheel feeding mechanism is provided to control thefeeding movement and adjustment of the grinding wheels toward and fromthe crankshaft 33 to be ground. Independent feed controlling mechanismsare provided for each of the wheel slides 2| and 22, respectively,

asa'a narchine by a manually operable feeding mechanism to behereinafter described.

In order that the wheel slide 2| may be rapidly moved toward and fromthe crankshaft. to grind the crankpins thereon by the, plunge-cutmethod, the feed screw 3| is connected to a piston rod 32. A fluidpressure. cylinder 33 is arranged inaxial alignment with the feed screwon the work i 3| and containsgs slidablyimoiinted piston .34 which isconnected to or formed integral with the piston rod 32. A fluid pressurepump (Fig.

. 3) is mounted to be driven by an electric motor 33 which may bestarted and stopped-by a push button switch 4| (Fig. 1) located on theleft hand end of the machine. The pump 33 is arranged to force fluidunder pressure through a pipe 31 from a reservoir 33 within the base 23.The pump 33 forces fluid under pressure through the pipe 31 to a valvechamber 33 in a feed control valve 33. The feed control valve 33 is apiston type valve comprising a valve stem 3| having valve pistons 32,33, 34, and 63 formed in- I tegral therewith.

In the position of the valve 33 (Fig. 4), fluid under pressure enteringthe valve chamber 33 located between the valve pistons 33 and 34 passesoutwardly through a pipe 61 into a cylinder chamber 33 to cause thepiston 54 to move rearwardly so as to move the wheel slide 2| and thegrinding wheel 23 to its rearward or inoperative position away from thecrankshaft 33 being around. During the passage of fluid into thecylinder chamber- 33. fluid is exhausted from acylinder chamber 33,through a pipe 13, into a valve chamber 1| located between the valvepistons 62 and 33, and out through a pipe 12 which exhausts into thereservoir 33. -The exhaust from the controlvalve 33 passes through twovalves in the pipe 12 which can be adjusted to throttle the exhaust tocontrol the hydraulic functioning of the various elements of the machineconnected to the control valve 33. a r A manually operable control lever13 is pivotally mounted on a stud 16 which is in turn carried by abracket 11 mounted on the front or the machine base 23. The lever 13 1soperatlvely connected by means of a pin 13 with the valve stem 3| bymeans-of which movement of the lever 13 so that each wheel may be fedindependently of the other wheel. In the preferred construction,however, the two controlling mechanisms arearranged so that the grindingwheels may be fed simultaneously into grinding contact with the workpiece to be ground by means of a control adjusting the wheel slide 2| insetting up the ma- 7; to be ground, to grind crankpinsfthereon by theserves to move the valve stem 6| in either direc- 3 tion, depending uponthe direction of movement of the lever 13. When it is desired to causean infeeding movement of the grinding wheel 23, the

control lever 13 is moved in a counterclockwise direction (Fig. 4) tomove the valve stem 3| downwardly, which movement serves to cause fluidunder pressure entering the valve chamber 33 to pass outwardly throughthe pipe 13 into the cylinder chamber 33 to move the piston 54 and thefeed screw 3| to cause a forward feeding movement of the wheel slide 2|and 23. Similarly, a fluid pressure wheel feeding mechanism is providedto control. the feeding movement and adjustment of the wheel slide 22.The wheel slide 22 is provided with a-depending half nut 33 (Fig. 2)which meshes witha rotatable feed screw 3|. The feed screw 3| isrotatably supported in hearings in the longitudinally movable slide 33.Thei'eed screw 3| may be rotated manually for adjusting the position ofthe" wheel slide 22 in setting upthe machine by. a manually operablefeedingmechanism to be here inafter described. j In order that the wheelslide 22 may be rapidly moved toward and from the crankshaft 33 thegrinding wheel.

plunge-cut method, the feed screw II is connected to a piston rod 92. Afluid pressure cylinder 99 is arranged in axial alignment with the feedscrew 9| and contains a slidably mounted piston 99 which is connected toor formed integral with the piston rod 92. A fluid pressure pump 95 ispreferably formed as a tandem or duplex pump combined with the pump 99and is driven by the electric motor 99. The pump 99 forces fluid underpressure through a pipe 99 from the reservoir 99 within the machine base29. The pump 99 forces fluid under pressure through the pipe 99 into avalve chamber 91 of a'feed control valve 99. The valve 99 is preferablya piston type valve comprising a valve stem 99 having formed integrallytherewith valve pistons 99, 9I, 92, 99 and 99. I

In the position of the valve 99 (Fig. 4), fluid under pressure enteringthe valve chamber 91 passes outwardly through a pipe 99 into a cylinderchamber 99 to cause the piston 99 to move rearwardly to withdraw thewheel slide 22 and the grinding wheel 29 to a rearward or inoperativeposition away from the crankpins of the crankshaft 99 being ground.During the passage of fluid under pressure into cylinder chamber 99 tocause a rearward movement of the piston 99, fluid is exhausted from acylinder chamber 91, through a pipe 99, into a valve chamber 99 locatedbetween the valvepistons 99 and 9|, and out through a pipe I99 whichexhausts into the reservoir 59. The exhaust from the control valve 99passes through two valves in the pipe I99 which can be adjusted in thesame manner as valves in the exhaust pipe 12, as previously de scribed.

A control lever I99 is pivotally mounted on a stud I99 carried by abracket. I91 on the front of the machine base. The control lever I99 isconnected by means of a stud I99 with the valve stem 99 by means ofwhich the control lever I99 may be actuated to shift the valve stem 99as desired to cause either a rearward or forward feeding movement of thegrinding wheel 29 and wheel slide 22. When it is desired to cause aforward feeding movement of the grinding wheel 29, the control le'verI9! is moved in a clockwise direction (Fig. 4) so that fluid underpressureentering the valve chamber 91 passes outwardly through the pipe99 into the cylinder chamber '91 to cause a forward movement of thepiston 99 to move the wheel slide 22 and grinding wheel 29 forward intoan operative position to grind a crankpin on the shaft 99.

A fluid pressure connection is provided between the feed control valves99 and 99. A pipe 9 is connected between the pipe 91 and a manuallyoperable valve III. A pipe II2.is connected between the valve III and acylinder chamber III at the forward end of the feed control valve 99. Inthe position of the valve I I I (Fig. 4) the valve chamber H9 isconnected through the valve I I I and a'pipe III with the exhaust pipeI99.

' Similarly, the forward movement of the valve stem 99 of the feedcontrol valve 99 maybe hydraulically controlled by the feed controlvalve 99. A pipe "I is connected between the pipe 19 and 'a manuallyoperable valve I92. A pipe I99 is connected between the valve I92 and acylinder chamber at the rearward end of the feed controllvalve 99, thischamber being similar to the feed control valve 99, the manuallyoperable valve in is actuated so that pipe no will be connected to pipeH2 and the valve I92 will remain in the position shown in Fig. 4. Whenthe control lever 19 is actuated to move the feed control valve 99forward, the pipe 91 is connected withthe exhaust, also the pipe II9.Consequently the control lever I99 may move the valve stem 99 forwardsince the fluid in the cylinder chamber III is not under pressure butexhausts through the pipe II2, valve III, and the pipes in and 61. Whenthe grinding wheels 2: she 29 have sparked out so that grinding iscompleted, the control lever 15 is moved rearwardly and the feed controlvalve 99 will admit pressure to the pipe 91 to move the grinding wheel29 to an inoperative position. When the pipes 91 and H9 are connected topressure, fluid under pressure passing therethrough moves the valve stem99 rearwardly, admitting pressure to the pipe 95 to move the grindingwheel 29 to an inoperative position.

If it is desired to have the feed control valve 99 hydraulically actuatethe forward movement of the valve stem 99 of the feed control valve 99without the operator touching the control lever I99 and to have theoperator manually control the rearward movement of thevalve stem 99,this may be accomplished by turning the manually operable valve I92 sothat the pipe I9I will be connected to the pipe I99 and the valve IIIwill remain in the position shown in .Flg. 4. This setting of the valvesI92 and III order to reduce the rapid approaching movement to apredetermined grinding feed, it is desirable to provide a fluid pressurecontrolling mechanism, such as a dash pot mechanism, which may berendered effective when the grinding wheels 29 and 29 are about tocontact with the surface of the crankpins to be ground. As illustratedin Fig. 4, the cylinder 991s provided with a casing II9 which contains apair of diametricalLv opposed dash pot pistons H9 and H1 which slidewithin dash pot cylinders H9 and H9. The

, dash pot pistons II9and 1 are normally held the chamber H9 at theforward end. In this position of the valve III (Fig. 4), therearward endchamber is. connected, through the valve I92 and a pipem. w h t e pipesk I! in rearward position by springs I99 and III, respectively. Duringthe rapid approachingmovement of. the grinding wheel 29, the dash .potpistons H9 and H1 are ineffective. The .pis-

ton rod 92 extends toward the rear of the ma.-

chine and is provided at its rear endnwith a sleeve I22 which may beadjusted longitudinally on a threaded portion I99 of the piston rod 92I22 moves rearwardly 'a' predetermined size.

a rapid approach until the means of a lock nut I63.

ment continues until the end of the sleeve I22 engages the ends ofthedash pot pistons H6 and ton 64 is retarded by the dashpot pistons II andH1 which force fluid under pressure from the dash pot chamber through aneedle valve I21 into a reservoir I28.

' wheel 24 and its supporting slide 22. This mech- 1,. afterwhich'continued movement of the pis-.

anism comprises an adjustable stop sleeve I68 which surrounds the sleeveI42 and is arranged to engage a stop surface I66 formed on the rearsurface of the dash pot casing I35. The sleeve I56 is threaded onto athreaded portion I61on the periphery of the sleeve I 42 and is arrangedto be held in adjusted position thereon by means of a lock nut I58.

Manual feed adjustment Each'of the feed screws 6| and M are arranged sothat they,may be manually rotated independ- Similarly, a casing I36 isfixedly mounted on I the end of the cylinder 83 and contains a pair ofdiametrically opposed dash pot pistons I36 and I31 which slide withindash pot cylinders I38 and I36, respectively. The dash pot pistons I36and I31 are normally held in a rearward provided at its forward *outerend of the shaft I62 carries a position by springs I40 and I,respectively.

During the rapid approaching movementnof the grinding wheel 24, the dashpot pistons I86 and I31 are ineffective. The piston rod 82 extendstoward the rear of the machine and is provided at its rearward end withan adjustable sleeve I42 which may be adjusted longitudinally onathreaded portion I43 of the piston rod 82 and locked in. adjustedposition by means of a lock nut I44. The parts are so arranged that thesleeve I42 moves rearwardly when the piston 84 moves into a rearwardposition. The dash pot pistons I36 and I31 are limited in their rearwardmovement by means of adjusting sgrews I45 and I46. respectively.

When fluid under pressure is admitted to the cylinder chamber 31 tocause the grinding wheel 24 to move toward the crankshaft 88, the rapidapproaching movement continues until the end of sameas the sleeve I42engages the ends of the dash potpistons I36 and I31. after whichcontinued movement-ofthe piston 84 is retarded by the dash pot pistonsI86 and I31 which force fluid under pressure from the dash pot chambersthrough a needle valve I41 into a reservoir I48. By regu lation of theneedle valves I21 and I41. respectiveLv, the rate of grinding feed maybe readily adjusted as desired.

Positive stop In order to grind a work piece to a'predeter1-.

the forward movement the dash pot pistons grinding infeed whichcontinues until an adjustable "stop sleeve 168 III on the :rear faceengages a fixed end surface of the dash potcasingilIS, thereby limitingthe infeedingmovement of the grinding wheel 23 and the wheel slide 2I tocause a dwell of the wheel in contact with the w mounted on one arm anda solenoid I84 work during a finish grinding period. The adjustable stopsleeve I 60 surrounds the sleeve I22 and is threaded thereto .by-me'ansof a thread I62 and held in adjusted position thereon by either during atruing operation or hand wheel ne- (Fig. 5).

ently to adjust the position of the wheel slides 2I and 22 when desired.The feed screw II is end with a bevel gear I66 which meshes with a bevelgear I6I mounted on the inner end of a rotatable shaft I62. The gear I63meshing with a gear I64- .carried byv a rotatable shaft I66 which alsosupports a manually operable feed wheel'I66.

The feed screw ,8I may be rotated manually bya similar manuallycomprising a bevel gear I10 which meshes with a bevel gear "I carried onthe Inner end of a rotatabl shaft I12. The shaft I12 supports a gear I13which meshes with a gear I14 on a shaft I16. A manually operable handwheel I16 is I mounted on the outer end of the shaft I16. To facilitateadjusting the feed screws from the operator's station in front of themachine,

v to compensate for wheel wear, an electrically controlled mechanism isprovided automatically and incrementally to advance the wheels 28 and24,- respectively, by desired and predetermined increa ments. Thismechanism is substantially the that disclosed in the prior' U. S. patentto Wallace H. Wood and Carl G. F'lygare, No. 2;151,669 dated March21,1939, to which. reference may be had for details of description notcontained herein. The feed screw II may be automatically adjusted fromthe front of the machine by means of a pawl and ratchet mechanismcomprising-a ratchet wheel I18 mounted on the hand wheel I88 and a pairof pawls I13. The pawls I18 are of a bell crank lever I88 which isactuated by means of a fluid operated piston I8I which is slidablymounted within a cylinder I82. A control valve I83 serves to control theadmission of fluid to the cylinder I82 is provided for actuating thevalve I83. A push button I 88 is provided on the front of the machinebase whereby the solenoid I84 may be energized when desiredto rotate thefeed screw 6| by a desired and predetermined amount incrementally toadjust the position of the grinding wheel 23. The extent of movement ofthe feed pawls I19 is controlled by a pair 5 f opposed adjusting screwsI86 and I81which are arranged in the path of an arm I88 formed 'integralwith the bell crank lever l8l.

Similarly, the feed screw 8| maybe adjusted from the control station infront of the machine by means of a ratchet wheel I 30. mounted on theThe ratchet'pawls I6I a bell crank lever I22 of a piston I63. The

are carried by one arm'of which is rocked by means piston is: isslidably mounted within a cylinder I94. A control valve I85, serves tocontrol the operable feed mechanism admission of fluid to the cylinderI34. A solenoid I33 is provided for actuating the valve III. A pushbutton switch I31 is mounted adjacent to the operator's control stationwhereby the solenoid I33 may be readily actuated to provide the desiredincremental feeding movement of the screw 3| for adjusting the positionof the grinding wheel 24 and its supporting slide 22 to compensate forwheel wear or during a truing operation.. A pair of opposed adJustingscrews I33 and I33 are provided to facilitate adjustment of the strokeof th pawls "I. These adjusting screws are mounted on opposite sides ofan arm 233 which is formed integral with or fixedly mounted tothe bellcrank lever I32. A snap switch 2M (Fig. 1) is provided, by means ofwhich bo'thgrinding wheels 23 and 24 may be incrementally fedsimultaneously by actuation of either of the push button switches I33and I31. It will be readily apparent from the foregoing disclosure thatby means of the remote electrical control above described, both thegrinding wheel 23 and the grinding wheel 24 may be adjustedby one ormore increments when desired from the operators control station in frontof the machine.

The longitudinally movable slides 31 and 33 are providedwith poweroperated indexing or traversing mechanisms which in the preferred formare hydraulically operated. A cylinder 233 mounted on the base 20 of themachine contains a slidably mounted piston 233. The piston 233 isconnected by means of a piston rod 231 with a bracket 233 which isfastened to the left-hand end of the slide 31. The admission to andexhaust of fluid from the cylinder 235 is controlled by a control valve233 which will be hereinafter described. A similar mechanism is providedfor controlling the indexing or traversing movement of thelongitudinally movable slide 33, comprising a cylinder 2 which containsa slidably mounted piston 2". The piston 2l3 is connected by means of apiston rod 2" with a bracket 2" which is fixedly mounted on theright-hand end of the slide 33. The admission and exhaust of fluid fromthe cylinder H3 is controlled by a control valve 2i3 which will behereinafter described.

Work support The crankshaft 33 to be ground is rotatably supported by apair of spaced aligned work heads 223 and MI which are provided at theirinner ends with rotatably mounted pot chucks 222 and 223, respectively.These pot chucks 222 and 223 are fixedly mounted on the ends of a pairof aligned rotatable spindles which are journalled in suitable bearings(not shown) within the heads 223 and 22I, respectively. The details ofdisclosure of the spindle construction have not been illustrated sincethis feature is not considered to be a part of the present invention andsince the structure thereof is substantially identical to that shown inthe prior U. S. patent to Herbert A. Silven, No. 2,151,666 dated March21, 1939, and U. S. patent to Herbert A. Silven, and Albert G. Belden,No. 1,837,342 dated February 22, 1931, to which reference may be had fordetails of disclosure not contained herein.

The pot chucks 222 and 223 are driven by sprockets 224 and 223 which aremounted on the outer ends of the rotatable work spindles. The sprockets224 and 223 are connected by link chains 223 and 221, respectively, withsprockets 223 and 223, respectively, which are in turn subported onopposite ends of arotatable drive shaft 76 233. The drive shaft 233 isiournalled in suitable bearings within the base of the machine.

A driving mechanism is provided comprising an electric motor 231 whichis supported on the base of the machine. The electric motor 23| isconnected by a multiple V-belt 232 with a pulley viously describedsynchronously to rotate the pot chucks 222 and 223 uniformly to driveand rotate the opposite ends of the crankshaft 33 to be round.

In a crankshaft grinding machine of the type illustrated, it isdesirable to stop the pot chucks 222 and 223 in upright positions tofacilitate the loading operation. A motor brake switch 243 is providedfor stopping the motor 23i at the desired and predetermined time to stopthe pot chucks. The motor brake switch 240 is controlled by a cam 2 anda normally closed trip switch 242.

When the valve 63 is shifted to its rearward position, a cam surface ona cross-shaped head 333 opens the normally closed limit switch 334 tobreak the circuit. Similarly when the valve 33 is shifted to itsrearward position, a cam surface on a cross-shaped head 343 opens thenormally closed limit switch 344 to break the circult. The two limitswitches 334 and 344 are preferably connected in parallel so that it isnecessary for both Brinding wheels to be in an inoperative positionbefore the work holders 222 and 223 may be automatically stopped in apredetermined loading position. when the circuit through the limitswitches 334 and 344 is broken, a solenoid 233 on the work head 223 isdeenergized to release the tension of a spring. This movement serves torock a lever 239 into the position shown in Figs. 2 and 4, to move aslidably mounted rod 243 so that a roller on the end of the rod ridesupon the periphery of a cam 2. The cam 24! is mounted on a sleeve (Fig.4) to rotate with the work supporting spindle.

The motor 23l for rotating the work support ing pot chucks 222 and 223is preferably of a type which is controlled by a magnetic reversestarter switch and a motor brake switch 243 so that the rotation of themotor 23l may be stopped in a predetermined position after a grindingoperation has been completed. As shown in the electrical diagram (Fig.4), the motor 23l is controlled by a magnetic starter reverse relay 244which controls the forward and reverse fields of the motor 23 l When thesolenoid 233 is 'deenergized, the roller mounted on the rod 243 is movedby the spring actuated lever 233 into contact with the cam 24 I. Themovement of the roller on the rod 243 into operative contact with thecam 2 serves to open a normally closed trip switch 242 which opens thecircuit and cuts the power from the power field of the motor 23l. Thismovement serves through the motor brake switch 243 to actuate a magneticmotor reverse relay 253 which serves instantaneously to reverse thecurrent in the motor 231 and, through the motor brake switch 243, tostop the motor 23| so that the work holders 222 and 223 are inpredetermined positions.

. A safety relay 233 is so connected as to render the power circuitinoperative in case the electric current fails. Upon failure of theelectric current supplied to the driving motor 23!, the safety j relay259 opens and before the work rotation can be again started, a makecontact reset push button 280 must be pushed to close the circuit. Thismovement in turn serves to close the safety relay 244 and thereby againstart the rotation of the motor 23l. A make contact push button 28lserves as a jogging switch to jog the rotation of the work if desired. Adoubl pole snap switch 282 serves in one position to permit a Jogging ofthe work rotation by the push button 2M or in the opposite positionshown in Fig. 4 serves to start the rotation of the motor 23l. A doublepole snap switch 283 serves in one position to render the automaticcontrol of the work rotation inoperative to facilitate manual control topermit jogging of the work rotation as desired, and in the positionshown in Fig. 4 serves to render the automatic control of the workrotation operative. By manipulation of the push buttons 286 and 28l andthe snap switches 282 and 283, the

rotation of the work drive motor 23] may be readily controlled asdesired, A relay 284 serves to control the use of the motor brake switch246 by braking the circuit through one of the contacts in the starterreverse relay 244 which controls the motor reverse relay 258.

It is not deemed necessary to fully describe the work stop controlmechanism in the present case since this feature is not considered to bea part of the present invention and since the mechanism is substantiallyidentical with that shown in the prior U. S. Patent to Herbert A.Silven, No. 2,151,666 dated March 21, 1939, to which reference may behad for details of disclosure not found herein.

A push button switch 280 (Figs. 1 and 4) is provided for controlling thestarting and resetting of the work drive motor 23l. The pot chucks 222and 223 are spring clamped and hydraulically released, as is shown inthe prior patent to Silven above mentioned. A cylinder 245 mounted onthe left-hand end of the machine (Figs. land .4) contains a slidablymounted piston 246 which is journalled to one end of a piston rod 241the other end of which iSJon-nected to release the clamping action ofthe pot chuck 222 at the left-hand end of the crankshaft 30.

A cylinder 248 is mounted on the right-hand end of the machine andcontains a slidably mounted piston 249 which is journalled to one end ofa piston rod 250. The other end of the piston rod 250 is connected torelease the clamping action of the pot chuck 223 on the right-hand endof the crankshaft 36. The cylinder 245 contains a cylinder chamber 25!which is connected by means of a pipe 252 with a pipe 253 which isconnected with the control valve 88. The cylinder 248 contains acylinder chamber 254 which is connected by a pipe 255 which connectswith the pipe 253.

From this construction it will be readily apparent that fluid underpressure passing through the pipe 253 will b simultaneously admitted tothe cylinder chambers 25| and 254 simultaneously to release the clampingaction of the pot chucks 222 and 223 after a grinding operation has beencompleted. A pipe 256 is connected between the control valve 60 and thecontrol valve 88 so that fluid under pressure cannot be passed throughthe pipe 253 to unclamp the work until both the control valve 60 and thecontrol valve 88 are in their rearward positions to move the grindingwheels 23 and 24 to their rearward r inoperative positions. In theposition shown in Fig. 4, fluid under pressure from the pump enteringthe valve chamber 59 passes through a pipe or passage 25! and through avalve chamber located between the valve pistons 65 and 66 (Fig. 9),through the pipe 256, tothe control valve 88, through a valve chamberlocated between the valve pistons 93 and 94, and outwardly through thepipe 253 and simultaneously through the pipes 252 and 255 to move thepistons 246 and 249 into the positions illustrated in Fig. 4jto unclampboth of thepot chucks 222 and 223. The connection between the pipes 256and 251, when the valve chamber between the valve pistons 65 and 66 isaligned with the pipes for fluid pressure, is directly opposite portholes (Fig. 9). The construction is the same in the other feed controlvalve.

steadyrest In the preferred construction, a pair of steadyrests 260 and26l are provided for simultaneously steadying opposed aligned crankpinson the crankshaft 30 during simultaneous grinding thereon. Thesteadyrests 260 and 26l are preferably arranged so that they may bemoved vertically to and from an operative position to facilitatetraversing or indexing the rests by and in timed relation with theindexing or traversing of the grinding wheels 23 and 24, respectively.

The steadyrest 260 is provided with a transversely adjustable steadyrestshoe 262, The transversely movable shoe 262 is supported on a verticallymovable slide 263. A fluid pressure mechanism is provided for moving thesteadyrest shoe 262 and the slide 263 vertically to and from anoperative position,

.having a slidably mounted piston 265 which is connected to one end of apiston rod 266. The lower end of the piston rod 266 is operativelyconnected to the vertically movable slide 263 so that when fluid underpressure is admitted to the cylinder chamber below the .piston 265, theslide 263 together with the steadyrest shoe 262 will be moved verticallyinto an operative position. It is desirable that the steadyrest shoe 262engage, support and steady the crankpin being ground, and that thesteadyrest be indexed longitudinally to position it successively inoperative relation with successive crankpins on the shaft 30. The fluidpressure cylinder 264 is, preferably formed as an integral part of asteadyrest frame. The steadyrest frame is provided with two slide-. wayswhich mate with correspondingly shaped slideways 261 and 268 on theupper surface of the base 26 (Fig. 2). The frame of the steadyrest 260has an integral rearwardly extending portion 269 (Fig. 10) which is.flxedly fastened to the longitudinally movable slide 31 by means ofwhich the steadyrest 266 may be traversed or indexed by and in timedrelation with the longitudinally movable slide 31 when the grindingwheel 23 and its supporting wheel slide 2| are indexed longitudinallyinto operative position with relation to successive crankpins on thecrankshaft 30 to be ground.

Similarly, the steady'rest in (Figs. 1,2 oh 4) Ii. provided with atransversely odiustebie restshoefll whichis carriedbyavertically'movableslide "I (Fig. '1). The slide I'll is moved.

in'a'verticali direction by ailuid pressure cylinj der II! which has asiidably mounted piston ill contained therein. 'lhe piston Ill isconnected control knoblll'is toward the right solilllitfllllllllllllloi'li l'fllll'eellliel'lllgthevalve jthepiston ll.andthe slide lltogetherwlth the to theupper end of a piston rod I'll.the'lower'.

endof which is flxedly connected to the vertically sure through the pipell, fluid under pressure will also be passed through the pipe-Ill toraise the steady restlll to an operative position. 'e steadyrest Ill issimilarly hydraulically. connected with the control valve ll. A pipe 2'"is connected with the pipe ll so that when fluid under pressure isadmitted throughthe pipe ll to cause a rearward movement or the grindingwheel ll, fluid will be simultaneously passed through grindingwheel lltoward the right. During the -movementof-the piston Ill toward therlght.

movable slide'lll. The cylinder Ill-is formed fluid withinfa cylinderchamb'er' Ill exhausts integral with the frame of the steadyrestlll.through .apipe ill, through a valve chamber in The frame of thesteadyrest lll is provided with the control valve Ill, and out throughan adslldeways mating with the'slideways Ill andlll. Justable throttlevalve Ill and adjustable valve (Pig. 2) and has an integral rearwardlyextendill and a pine Ill to the reservoir ll. ing portion znwhieh isfastened to the longituis i y. i it is desired to i e he wheel dinallymovable slide a so that the steadyrest I tow d the left. the knob m ismoved toward rliwill be indexed in traversed longi y by the left s 't td under preeeu e'e e i s t e and in timedrelation with the indexingmovevalve chamber Illpasses thro sh the'pil eat of the grinding wheel :4as it is su'ccesi the lin er ha m v he-piston sively indexed forgrindiiig-plns on the crankgo l the. Built lLtoscther with, the grlndins3g wheel ll toward the left. During the movement It is desirable thatthe steadyrest. shoe m :of the piston II toward the leftrfluid exhaustsbe moved into operative engagement with the from. the cylinder chamberll. throu h the pipe work a in timed relationship with the move- I her-om valve "t pipe "I. to a v lve merit of the grinding wheel ,fl towardoperam in the control V v l, and out throug tive position. A pipe I'llis. connected between Q lilflt lo hr t le valve Ill and valve. 299 thepipe ll anda cylinder chamber n in the which connects with e exhaust pI" into cylinder in so that when flllid under pressure ihereeervoir II.By adiustins the throttle valves is admitted to cause a rearwardmovement of the m. n "I. the sp ed of in v ment grinding wheel ll, fluidunder :pressure' will be of the grinding Wheel 1 m y be ependentlysimultaneously admitted to the uppercylinder i d-- chamber!" to move thesteadyrest Ill'downe r v rsing r indexing m v ment oijthe wardly to aninoperative position. A pipe 1" .8rlnding wheel 24 is controlled ina'similar man-- M t cylinder (,Mmber below the piston her by thecontrol'valve ill which is actuated by m with e valve chamber locatedbetween the knob "L Fluid under pressure iromthe p valve pistons s: andu and in the position of the through the r it verses us control valve ll(Fig. 4t) fluid exhausts there- P199 a Valve chamber when it fromthrough t pipe 11 t nreadily desiredto index the grinding wheel 24toward the parent from the foregoing disclosure that when the con 0 ismoved the the "me u is hift d t admit fluid under pres left so thatfluid under pressure'entering the valve chamber ll! passes out through apipe-ill to the 'by-pass valve ill, through a pipe lll, into a cylinderchamber IN to move the piston Ill and grinding wheel 24 toward the left.During the movement of the piston 2 il toward the left, fluid within acylinder chamber 3" exhausts through a pipe lll to the control valveIll,- passes through a valve chamber in the central valve 1 ll, andthrough aniadjustable throttle valve lll, ad-

the pipe 1'" into the upper cylinder chamber 2" lo Jumble valve and anexhaust P of the cylinder I'll to cause the piston I'll to movedownwardly into the position illustrated in Pig. 4, moving thesteadyresttoan' inoperative position. A pipe Ill is connected betweenthe lower cylinder chamber of the cylinder 21! and a valve chamber lllocated between thevalve pistons ll and ll of the control valve ll. Inthe position of the valve ll (Fig. 4) fluid exhausting through the pipeIll into the valve chamber ll will exhaust through the pipe Ill into thereservoir ll. When the control valve ll is moved to admit fluidunder'pressure through the pipe ll to cause a forward feeding movementof the grinding wheel 24, fluid under pressure is passed through thepipe lllto cause the piston 213 togetherwith the steadyrest Ill to-moveupwardly into an operative position.

Wheel index control The control valve Ill is a" piston type valve whichis manually controlled by a knob Ill.-

the reservoir ll. g

Similarly, if it is desired to index the grinding wheel N toward theright, the'knob "I is moved (let the il'l dlnl wheel ll towardth'eright, the 7Q toward the right so that fluid within the valve chamberIll passesjoutwardly through the pipe 3" into the cylinder chamber lll.During this movement, fluid within the cylinder chamber lll through thepipe lll, through the by-pass valve ill, the pipe Ill, to the controlvalve I'll, through aevalve chamber in the control valve 2 l l, andthrough an adjustable throttle valve Ill and adjustable vdlvem and'an'exhaust pipe as into reservoir ll. It will be readily apparent from theforegoing disclosure that by manipulation of the throttle valves lll,ill and Ill, the speed of the indexing movement-of the grinding wheel 24may be independently varied in its movement in either direction.Spring-pressed detents Ill and ll! are provided to engage notches I lland lll when the control valves llland Ill are in a central or neutralposition. I

- Eli-m8 valve The by-pass valve Ill is a normally closed valve inwhich'a spring I ll normally holds a valve pipe 253 (Fig. 4) andsimultaneously through pipe' 255 the pot chucks 222 and 223,respectively, are

unclamped after'a grinding operation hasbeen completed. Fluid under'pressure also passes through a valve 320, through an adjustable throttlevalve 32!, into a valve chamber 322, to move the piston 3". into theposition illustrated in Fig. 3, in which position fluid may readilyby-pass between the pipes 303 and 304 and between-the pipes 283 and 230,thus rendering the longitudinal wheel indexing mechanism operative sothat the grinding wheels 23 and 24 may then be indexed longitudinally toposition them for grinding the next pair of aligned pins on thecrankshaft 30.

In case it is desired to render the by.-pass valve 283 inoperative, thevalve 320 may be turned to the opposite position (Fig. 3), in whichposition fluid under pressure is admitted through an extension of thepipe 51 to move the piston 3" to the right, as shown, so that fluid mayflow freely at all times into the cylinders 205 and 2!15. A pipe 323is'connected between the pipes 233and 230. A pipe 324 is connectedbetwen the pipes 303 and 304. The pipes 323 and 324 are shunted aroundthe by-pass valve 233 and each pipe has an adjustable valve which isnormally shut off, but when the valve 320 is turned to direct pressure,the valves in the pipes may be opened to shorten the passage of fluid.If desired, the valve 320 may remain as shown in Fig. 3 and the valvesin the pipes 323 and 324 may be opened to shunt fluid around the by-passvalve 283.-

. Interlock It is desirable tween the transverse feeding and thelongitudinal indexing movements of the grinding wheels so that thegrinding wheels cannot be indexed longitudinally until the wheel feedcontrol valves have been shifted to cause a movement of the grindingwheels to a rearward or inoperative position. The interlock mechanism isalso provided with an electrical interconnection whereby the work drivemotor 23! is' stopped by and in timed relation with the movement of thefeed control valves 60 and 88 to a position to cause a rearward move-.

ment of the grinding wheels 23 and 24, respectively. The hydraulicinterlock comprises a. plurality of parallel fluid pressure cylinders325, 328, 321 and 323 which are arranged around the periphery of therear end of the control valve 30 to provide a fluid interlock beinseam?tor 23i automatically stops.

I The pipe 233, in addition to being connected with the cylinder chamber232 of the wheel traversing or indexing cylinder 205, is operativelyconnected with the cylinders 325 and 335.- The pipe 238 is similarlyconnected with the cylinders 323 and 333. The pipe 301 is connected withthe 303 is concylinders 321 and 331 and the pipe nected with thecylinders 323 and 333.

The mechanism previously described serves as an interlock between thetraversing mechanism for indexing the grinding wheels 23 and 24longitudinally and is arranged so that if the traverse control valves203 or 2|3 are shifted from neutral or central positions while thevalves 60 and 83 are in a wheel feeding position, the passage of fluidthrough the pipes 283, 233, 303 or 301 will pass into the chambers ofthe cylinders 325, 323, 321, 323, 335, 336, 331 or 333 automatically toshift the feed control valves 30 and 88 to a rearmost position, whichmovement serves to admit fluid under pressure tocause the grindingwheels 23 and 24' I together with their supporting wheel slides 2!.

. transmit a longitudinal 'justed to allow (Fig. 6). The cylinders 325,323, 321 and 328 contain-slidably mounted pistons 323, 330, 33! and 332,respectively. All of the pistons are fixedly connected to thecross-shaped head 333 which is fixedly attached to the rear end of thevalve stem 6! The limit switch 334 is mounted in fixed relationship withthe valve 30 and is arranged so that it is actuated by the cross head333 when itmoves to a rearward position. The switch 334 is a normallyclosed switch which is opened, when the cross head 333 moves to itsrearward position to break the circuit so as to stop the rotation 01!the work drive motor 23!.

Similarly, a plurality of fluid pressure cylinders 335, 333, 331 and 338are symmetrically arranged around the peripheral rear end of the controlvalve 88. Slidably mounted pistons 333, 340, 34! and .342 are slidablymounted in the cylinders 335, 333, 331 and 338, respectively. 'I'he endsof the pistons 333, 340, 34! and 342 are fixedly connected to thecross-shaped he'ad 343 which is in 'index control valves and 22 to moverearwardly to an inoperative position. The wheels '23 or 24 cannot beindexed until the control valves 60 and 33 have been shifted to theirrearward'positions and fluid under pressure passed through the by-passvalve 283. g

The by-pass valve 283 cuts off either the exhaust or pressure line tothe cylinders 205 andv 2! 5 so that the pistons moved until fluid underpressure passing through the pipe 253 enters the valve chamber 322 tomove the by-pass valve 233 toward the right, thus allowing free passagethroughthe pressure or exhaust lines so that the the grinding wheel 23or 24. throttle valve 32! interposed between the valve rate of passagethat the action of the by-pass valve may be ada sumcient time intervalto elapse so that the grinding wheels 23 and 24 may move to theirrearward position before a longitudinal indexing movement may beinitiated. It will thus be seen that an interlock is provided betweenthe mechanisms so thatthe traverse or movement of the grinding wheels 23and 24 when the wheels are in a forward or grinding position.

A pair of adjustable stop screws 350' and 35! are supported in a bracket352 which is fixedly mounted on the base 20. The stop screws 350 and 35!are arranged in the path of the piston rods 201, and 2! 1. When thepistons 203 and 2!! are indexed toward each other to position thegrinding wheels 23 and 24 for grinding the crankpins 35 and 33 (Fig. 1),the stop screws 350 and 35! are engaged by the end face of the'pistonrods 201 and 2", respectively. By adjusting the screws 350 and 35!,theposition of the wheels 23 and 24 may be adjusted so as to align thewheels relative to the pins to "Send 2|6 cannot be pistons 206 or 2;will indexing movement to" The adjustable cannot be accidentally beground. Similarly. a

pair of adjustable stop screws 333 and 333 are supported in brackets 331and 333 which are fixedly supported on the base 23. The stop screws 333and 333 are arranged in the path of depending lugs 333 and 333 whichdepend from the brackets 233 and 213, respectively (Fig. .3). The stopscrews 333 and 353 serve to limit the indexing movement of the wheels 23and 23 as they are moved into the position illustrated in Fig. 1 whilegrinding the crankpins 3| and 32, respectively.

The grinding wheels 23 and 23 are indexed longitudinally under thecontrol of the manually operable valves 233 and 213 which are actuatedby the manually operable knobs 233 and 333, respectively. The wheels 23and 23 are indexed longitudinally into position for grindingsuccessively the pairs of crankpins 31-42, 33-33 and 33-33 by manualcontrol of the valves 233 and 213.

Spark sputum? device ,The crankshaft to be ground on a crankpin grindingmachine of this type is usually rough turned in a crankshaft lathe andthe crankpins are not always located accurately in a longitudinaldirection so that it is dimcult to locate the grinding wheels by meansof a sufilciently accurate indexing mechanism so that the grinding wheelwill grind equally on opposite side,

shown in the prior U. S. patent to Carl G. Flyga'reNo. 2,101,794 datedDecember 27, 1937, and

the patent to Herbert A, Silven No. 2,151,666

dated March 21, 1939, to which reference may be had for details ofdisclosure not containedv herein. A manuallyroperable lever 33! (Fig. 1)

spectively. The cylinder 313 is fixedly mounted relative to the base 23and contains a slidably mounted piston Ill. The piston 311 is connectedto a piston rod 312. A rack bar 313 is connected to the left-hand end ofthe piston rod 312 (Fig. 10) and is slidably mounted in a shoe 314. Therack bar 313 meshes with a gear 315 which is formed integral with ashaft 313 (Figs. 10 and l1). The shaft 313 is rotatably journalled in abearing 311 whichis fixedly mounted relative to the base 23. A gear 313is formed integral with the upper end of the shaft 313 and meshes with apair of opposed rack bars 313 and 333, respectively. The rack bar 313 isfixedly mounted to the under side of the longitudinally movable slide 31which carries the wheel slide 2|, and the rack bar 333 is fixedlymounted to the under side of the longitudinally movable slide 33 whichsup ports the transversely movable wheel slide 22. Guide blocks 331 and332 are provided for slidably supporting the rack bars 313 and 333 torinlgintain themuln operative mesh with the gear It will be readilyapparent from the foregoing disclosure that when fluid isadmittedthrough a pipe 333 intov a cylinder chamber 333 to move thepiston 31! toward the left (Fig. 10), this movement transmits acorresponding movement is mounted on the upper end of an oscillatable Istud 332. The mechanism contained within the casing 333 and the wheelslide 2| i identical with that shown in the patent to Silven abovereferred to and is operatively connected to move the wheel spindlesupporting the grinding wheel 23 in an axial direction as controlled bythe movement of the spark-splitting lever 33 I.

A similar spark-splitting lever 333 (Fig. 2) is mounted on the upper endof an oscillatable shaft 333. A mechanism. identical with the Silvenconstruction is contained within the casing 333 and serves to move thewheel spindle axially within its bearings to position the grinding wheel23 when the lever 334 is moved. As in the patent to Silven, whenthe'grinding wheels 23 and 23 are moved toward a grinding position underthe control of the valves 33 and 33, respectively, the spark-splittinglevers 331 and 334, respectively,

' are moved so that the grinding wheels 23 and 23, respectively, grindequally on their side faces as the wheels move toward the crankpin.

, the grinding wheels 23 and 24 in opposite directions to position thewheels successively in the full line positions, into dot and dashpositions 230 and 24a and into-positions 23b and 23!), re-

toward the left of the rack bar 313, which movement rotates the gear313, the shaft 313 and the gear 313 in a clockwise direction, whichmovement causes the rack bars 313 and 333 to move longitudinally inopposite directions, that is, to-

ward the left and toward the right, respectively, simultaneously to movethe grinding wheels 23 and 24 longitudinally away fromeach other.Similarly, when fluid under pressure is admitted through a pipe 333 intoa cylinder chamber at the left-hand end of the cylinder 313, it movesthe piston 311 toward the right (Fig. 10) to transmit a correspondingmovement toward the right-of the rack bar 313. Movement of the rack bar313 toward the right serves to cause a counterclockwise rotary movementof the gear 315, the shaft 313, and the gear 313, to move the rack bars313 and 333 toward the right and toward the left, respectively, whichtransmits 'a longitudinal indexing movement of the wheels 23 and 24 tomove them relatively toward each other into positions 23:: and 23a forgrinding the crankpins 33 and 34, respectively, and thereafter intopositions 23b and 24b for grinding the crankpins 35 and 36,respectively.

A stop mechanism is provided for limiting the longitudinal indexingmovement of the grinding wheels 23 and 23. A stop sleeve 333 isadjustably mounted on a threaded portion 333 of the piston rod 312. Alock nut 333 serves to hold the stop sleeve 333 in adjusted position.When the piston 3" is moved toward the left so that the crankshaft 33.Similarly, when the piston 31! is moved toward the right into itsright-hand end position, a stop screw 332 carried by a bracket 333 whichis fixed relative to the base 23 serves to limit a stop lug 333 which isfixedly mounted with respect to" the rack bar 313. When the lug 333engages the stop screw 332, it stops the movement of the piston 311toward the right and locates the grinding wheels 23 and 23 in posiis inturn fixedly supported relative to the base.

20. When the detent 385 moves toward the right (Flg.'10), the cam faceon the detent will engage and depress the actuating plunger 388 to closethe limit switch 381 and stop the longitudinal indexing movement of thegrindin wheels 23 and 24 in positions 23a and 24a, re-

spectively.

A control valve 400 is provided for control-- ling the admission to andexhaust of fluid from the cylinder 310. This valve is a piston typevalve which is controlled by a manually operable knob 40I. The valve 400is normally held in a central or neutral position by a compressionspring 402. Fluid under pressure from the pump 85 passes through a pipe403 into a centrally located valve chamber 404. When it is desired toindex the grindingwheels 23 and 24, the knob I is shifted either towardthe right or toward the left, depending upon the direction of movementit is desired to impart to the grinding wheels 23 and 24. When the knob40| is moved toward the left, fluid under pressure passing into thevalve chamber 404 passes out through a pipe 405 which connects with thepipe 385 to admit fluid under pressure to the cylinder chamber to theleft of the piston 3' (Fig. 10) to move thepiston to- .ward the right,which movement causes 9. Iongitudinal indexing movement of the wheels 23and 24 toward each other. During this movement, fluid exhausts from thecylinder chamber 384 through the pipe 383.

Similarly, when it is desired to index the grinding wheels 23 and 24 intheopposite direction,

assays? sides of the peripheral'rear end portionfofthe control valve 88.Slidably mounted pistons H8 and 4 are contained within the cylinders 414and I. The upper endsof the pistons Hi and 4" are fixedly connected to across head .4"

which is fixedly connected to the. rear end of the,

valve stem 80 of the control'v'alve 88. A normally closed limit switch 8is fixedly mounted so that its actuating plunger is in the pathof a camsurface on the cross head 8 so that when the cross head 4| 8 moves toits rearward position, it opens the limit switch 8 to stop the workdrive, motor 28L As previously explained,

both of the limit switches H3 and 8 in this modification must also beopen before the work drive motor 23! automatically stops.

The pipe 405 is operatively connected to th cylinders 408 and 4 so thatwhen fluid under pressure is passed through the pipes 405 and 885 tomove the piston 8H toward the right, fluid will also be admitted to thecylinders 408 and 4 to move the pistons 4| 0 and 8 together with thecross heads M2 and 4| 8, respectively,

- toward a rearward position to shift the control valves 60 and 88 to aposition to cause a rearward movement of the grinding wheels 23 and 24to move them to an inoperative position.

Similarly, the pipe 408 is connected to the "cylinders 408 and M5,respectively, so that when fluid under pressure is passed through thepipes 408 and 383 to cause a movement of the piston 8" toward the left,fluid will be admitted to the cylinders 408 and 5 to shift the controlvalves 80 and 88 to move the wheels 23 and 24 to a rearward orinoperative position.

A by-pass valve 420 is provided between the pipes 408 and 383 which isarranged so as to delay the passage of fluid either to or from thecylinder 310 a suflicient length of time to make 40' sure that thecontrol valves 80 and 88 are shifted to move the grinding wheels 23 and24 rearwardly to an inoperative position before the longi- 'tudinaltraversing movement of the grinding wheels 23 and 24 may be started andalso to that is, away from each other, the knob 40l is moved toward theright so that fluid under pressure entering the valve chamber 404 passesoutwardly through a pipe 408 which connects with the pipe 383 in amanner to be hereinafter describedto pass fluid under pressure to thechamber 384 so as to move the piston 3' toward the left (Fig. 10). Thevalve 400 controls the adjustable fast and slower truing speeds and iscontrolled and used in the same manner as the control valves 208 and2'l9 (Fig. 3).

A fluid pressure interlock is provided for interlocking the traversingmechanism with the wheel feeding mechanism in a manner similar to thatdescribed in connection with Figs. 3 and4. A 7

pair of cylinders 408 and 408 are. arranged on diametrically oppositesides, of the peripheral rear end of the control valve 80. Pistons H0and 4 are slidably mounted within the cylinders 408 and 408. The pistons4l0 and 4" are fixedly connected to a cross head 2 which is piston 425be readily make sure that the rotation of the work piece 30 is stoppedbefore the indexing movement of the grinding wheels takes place. Fluidpassing through the pipe 408 passes through an ad- Justable throttlevalve 42l' into a pair of cylinders 422 and 423 which are connected tomove a valve stem 424 toward the right (Fig. 10)'s0 as to shift thevalve piston 425 against the compression of a spring 428 so that fluidunder pressure may pass unrestricted between the pipes 383 and 408,respectively. By regulation of the valve 42l, the speed of movement ofthe valve may be varied as desired. It will apparent from the foregoingdisclosur that when the control valve 400 is shifted to produce alongitudinal indexing movement of the grinding wheels 23 and 24, suchmovement is delayed until the control valves and 88 are moved to removethe grinding wheels to an inoperative position and to stop the workrotation before the longitudinal indexing movement takes place. Theby-pass valve 420 operates on the pressure side of the system when fluidunder pressure is passed through the pipe 406 to cause a movement of thepiston 3' toward the left. Similarly, when fluid under pressure ispassed through the pipe 405 to produce an indexing movement of thepiston 3' toward the right, fluid under pressure in the pipe 405 passesthrough an adjustable throttle valve 426 to shift th valve piston 425 soas to allow exhaust of fluid to flow through the by-pass valve 429 fromthe pipe 383 into the pipe 496.

An electrically controlled valve 426 is provided for stopping thegrinding wheels 23' and 24 in positions 23a and 24a, respectively. Whenthe detent 395 engages the limit switch plunger 396 to close the limitswitch 391, it serves to close a circuit, thus energizing a solenoid 429to move a spring retracted valve stem 439 toward the right (Fig. In theposition illustrated in Fig. 10, fluid exhausting from the valve 499through a pipe 43l passes through a valve chamber located between valvepistons 432 and 433 'and out through an exhaust pipe 434. -When thesolenoid 429 is energized to move the valve stem 39 toward the right,fluid under pressure exhausting from the pipe 43i enters a valve chamberlocated between the valve pistons 435 and 432 which in this position isnot connectedto the exhaust, thus cutting oil the exhaust from the valve499 and stopping the indexing movement of the grinding wheels inpositions 230 and 24a, respectively.

An electrical control circuit is provided com: prising power lines 436which are connected to a stop and start push button switch 431 and apair of break contact push button switches 438 and 439 which areconveniently located at the left and right ends of the base 29 relativeto the operators control station in front ofthe machine. These latterpush buttons are connected in series with the limit switch 391 and thesolenoid 329. After the crankpins 33 and 34 have been ground with thegrinding wheels 23a and 24a, the indexing'movement of the grindingwheels may be initiated by opening either the push button 433 or thepush button 439 to break the circuit, thus deenergizing the solenoid429, and at the same time to shift the control valve 499 while holdingthe push button switch open until the detent 395 rides over the plunger396.

The control valve 499 is preferably located on the right-hand end of thefront of the machine base 29. In order to facilitate control of themachine, a second control valve 449 is provided which may be locatedadjacent to the left-hand end on the front of the machine base. Thisvalve 449 merely serves to convey fluid under pressure to an end chamber4 or an end chamber 442 of the control valve 499 to shift it either inone direction or the other against the compression of the spring 492 soas to cause an indexing movement of the grinding wheels in a mannerheretofore described. The function of the valve 449 is merely for theconvenience of the: operator so that indexing of the wheels may becontrolled when the operator is adjacent to. the left-hand end of themachine.

The operation of the machine will be readily apparent from the foregoingdisclosure. A crankshaft 39 is placed in position in the pot chucks, 222and 223, after which the control levers and I95 are shifted to shift thecontrol valves 69 and 93. During the initial movement of the controlvalves 69 and 39, fluid under pressure within the clamp releasecylinders 245 and 243 is exhausted, thus allowing the clamps to engageand clamp the work in position for grinding. vThe grinding wheels 23 and24 are then moved to an operative position to grind the pins 3| and 32simultaneously. As the wheels 23 and 24 approach the pins 3i and 32, thespark splitting levers 36i and 364 are manually adjusted by the operatorto equalize the grinding on opposed sides of the grinding wheels 23 and24.

I After the grinding has been completed on the pins 3i and 32, thelevers 15 and I are shifted to cause a rearward movement of the grindingwheels, after which the grinding wheels 23 and 24 maybe indexedlongitudinally to position them opposite the pins 33 and 34,respectively, in a manner hereinabove described. As the grinding wheels23 and 24 move to their rearward or inoperative position, the workrotation is stopped and the work clamps released to facilitate indexingof the crankshafts 39 so as to position the crankpins 33 and 34 with.their axes in alignment with the axis of rotation of the pot chucks 222and 223. The control valves 69 and 38 are then shifted again so that thegrinding wheels 23 and 24 simultaneously grindthe pins 33 and 34.

.After this grinding operation has been com,- pleted, the control valves69 and 66'are again shifted to move the grindingwheels to an inoperativeposition and the wheels are then indexed longitudinally to positions 23band 2412,

respectively, after which the crankshaft 39 is After the completion ofthe grinding of the pins 35 and 36, the wheels are again moved to theirrearward position to facilitate removal of the ground crankshaft andreplacement thereof with a new crankshaft to be ground. On the grindingof the second crankshaft, the grinding wheels 23 and 24 may remain intheir center positions adjacent to each other, that is, in positions 23band 24b, to grind pins 35 and 36 on the next shaft, after which thewheels are indexed outwardly away from each other to grind successivepairs of pins. This cycle of operation may then be continued onsuccessive crankshafts.

It will be readily apparent from the foregoing either grinding wheelunit may be operated independently to grind one or more portions on awork piece such as a crankshaft, or both grinding wheel units may beoperated simultaneously to grind successively pairs of aligned spacedpins on a crankshaft.

- It will thus be seen that there has been providedby this invention agrinding machine in which the various objects hereinabove set forthtogether with many thoroughly practical advantages are successfullyachieved. As many possible embodiments 'may be made of the aboveinvention and as many changes might be made in the embodiment above setforth, it is to be understood that all matter hereinbefore set forth orshown in the accompanying drawings is to be interpreted as illustrativeand not in a limiting sense.

We claim:

1. In a grinding machine having a base, a rotatable work supportincluding a pair of spaced work heads on said base, a pair of spacedrotatable grinding wheels, means simultaneously to feed said grindingwheels transversely simultaneously to grind a pair of aligned pins on acrankshaft, and means simultaneously to index the other control valve.

said grinding ,wheels longitudinally successively into alignmentiwithsuccessive pairs of pins on a crankshaft.

2. In a'grindin'g machine having a base, a 'ro- 1 tatable work supportincluding a pair of spaced work heads on aid base, a pair of spacedrotatable grinding wheels, means simultaneously to feed said grindingwheels transversely simultaneously to grind a pair of aligned pins on acrankshaft, and means simultaneously and automatically to index saidgrinding wheels longitudinally in opposite directions successively intoalignment with successive pairs of pins on a crankshaft.

3. In a crankpin grindlng machine having a base, a rotatable worksupport including a pair of spaced work heads on said base, a pair ofspaced rotatable grinding wheels, means lncluding an independent pistonand cylinder to feed said grinding wheels transversely simultaneously togrind a pair of aligned crankpins on a crankshaft, and means includingan independent piston and cylinder automatically to index said grindingwheels longitudinally and successively into alignment with successivepairs of pins on a crankshaft. 3

4. In a crankpin grinding machine having a base, a rotatable worksupport including apair of spaced work heads on said base, a pair'ofspaced rotatable grinding wheels, means including an independent pistonand cylinder to feed said grinding wheels transversely simultaneously togrind a pair of aligned crankpins on a cranktatablc grinding wheel and arotatable work support which are movable longitudinally and transverselyrelative to, each other, a piston and cylr support relative indertransversely to feed said grinding wheel and work support relatively.toward and from each other, a manually operable feed control valvetherefor, a piston and cylinder longitudinallyto traverse said grindingwheel and work to each other, a manually operable traversecontrol valvetherefor, and a fluid pressure interlock including a piston and cylinderoperative to shift th feed control valve-into a position to cause atransverse movement between the grinding wheel and work subvalvetherefor,

shaft, and means including a piston and cylinder simultaneously andautomatically to index said grinding wheels longitudinally in oppositedirections successively in alignment with pairs of aligned crankpins ona crankshaft.

5. In a crankpin grinding machine having a base, a'rotatable worksupport including a pair of spaced work heads on said base, a pair ofspaced rotatable grinding wheels, means including a fluid pressurepiston and cylinder mechanism to index said grinding wheelslongitudinally, means including a pair of independent pistons andcylinders each of which is connected to feed one of said grinding wheelstransversely simultaneously to grind a pair of aligned crankpins on acrankshaft, an independent manually operable control valve for each ofsaid cylinders, and fluid connections including a valve connectedbetween said control valves whereby fluid under pressure from one ofsaid control Valves serves to shift 6. In acrankpin grindingmachinelhaving a base, a rotatable work support including a pair ofspaced work heads on said base, a pair of spaced rotatable grindingwheels, means including a fluid pressure piston and cylinder mecha nismto-index said grinding wheels longitudinally, means including a pair ofindependent pistons and cylinders each of which is connected to feed oneof said grinding wheels transversely simultaneously to grind a pair ofaligned crankplns on a crankshaft, an independent manually operablecontrol valve for each of said cylinders, and fluid connectionsincluding a two-way valve connected between said control valves wherebyfluid under pressure from one of said control valves serves to shift theother control valve,'said fluid connections being arranged so that thesecond control valve may be moved in either or both directions by fluidunder pressure from the first control valve.

7. In a grinding machine having a base, a roport before a longitudinaltraversing movement may be initiated.

, 8. In a grinding machine having a base, a rotatable grinding wheel anda rotatable work support which are movable longitudinally andtransversely relative to each other, a piston and cylinder transverselyto and work support relatively toward and from each other, a manuallyoperable feed control a piston and cylinder longitudinally to traversesaid grinding wheel and work support relative to each other, a manuallyoperable traverse control valve therefor, a fluid pressure interlockincluding a piston and cylinder operative to shift the feed controlvalve, and fluid pressure connections between the traverse control valveand said interlock cylinder whereby the feed control valve isautomatically shifted into av position to cause a transverse separatingmovement between the grinding wheel and work support before alongitudinal traversing movement may be initiated.

9. In a grinding machine having a base, a rotatable work supportthereon, a longitudinally and transversely movable rotatable grindingwheel on said base, a piston and cylinder to feed said grinding wheeltransversely, a manually operable control valve therefor, a piston andcylinder to traverse said grinding wheel longitudinally to position itrelative'to the work support, a manually operable control valvetherefor, and a fluid pressure interlock between said valves to preventa longit dinal traversing movement of when it is in an inoperia fluidpressure interlock between said valves including a piston and cylinderoperatively connected to move said feed control valve transversely toseparate the grinding wheel and work support before a longitudinaltraversing movement may be initiated.

11. In a crankpin grinding machine having abase, a rotatable worksupp rtincludinga pair of spaced work heads on said base to support acrankshaft, a pair of spaced rotatable grinding wheels, meanssimultaneously to feed said grinding wheels transversely simultaneouslyo grind ali ned pins on the crankshaft, means simultaneously to indexsaid grinding wheels longitudinally and successively into alignmentwithsuccessive pairs of pins on a crankshaft, and an interlock whereby bothof the grinding wheels feed said grinding wheelthereon, a longitudinallycylinders, means to actuate said valves either inare automatically movedtransversely to an inoperative position before either of the grindinwheels, an independent fluid operated piston and cylinder to feed eachof said wheels simultaneously towardand from a pair of spaced alignedpins on said crankshaft, an independent fluid operated piston andcylinder to traverse each of said wheels simultaneously longitudinallyto po: sition the wheels successively into operative position withsuccessive pairs of aligned pins on said shaft, a manually operablevalve to control the passage of fluid pressure to said feed cylinder, amanually operable valve to control the passage of fluid under pressureto'said traverse cylinders, and a hydraulic interlock to prevent alongitudinal movement of said wheels except when the grinding wheels arein an inoperative position.

13. In a crankpin grinding machine having a base, a rotatable worksupport thereon, a pair of spaced rotatable grinding wheels, independentmeans to traverse each of said grinding wheels either independently orsimultaneously, an independent piston and cylinder to feed each of saidgrinding wheels transversely simultaneously to grind a pair of spacedaligned pins on a crankshaft, independent control valves for each ofsaid cylinders, means to actuate said valves either, independentl orsimultaneously, an independent manually operable nut and screw mechanismassociated with each of said pistons and cylinders to facilitateadjustment ofsaid grinding wheels relative to said pistons, anindependent pawl and ratchet mechanism to actuate each of said nut andscrew mechanisms, and electrically actuated means including a solenoidoperatively connected to actuate said pawl and ratchet mechanisms eitherindependently or simultaneously.

pendent piston and cylinder to feed each of said grinding wheelstransversely simultaneously to grindapairofspacedalignedpingonacrankshaft, independent control valves for each of said dependently orsimultaneously, an independent manually operable nut and screw mechanismassociated with each of said pistons and cylinders to facilitateadjustment of said grinding wheels relative to said pistons, andelectrically actuated means to actuate said nut and screw mechamsmseither independently or simultaneously.

15. In a'crankpln grinding machine as claimed in claim 14, thecombination with the parts and features therein specified, ofindependent pistons and cylinders independently to actuate each of Isaid pawl and ratchet mechanisms, and electrically actuated valvestherefor independently or simultaneously to actuate said pawl andratchet feeding mechanisms.

16. In a crankpin grinding machine as claimed in claim 14, thecombination with the parts and features therein specified, ofindependent pistons and cylinders independently to actuate each of saidpawl and ratchet mechanisms, independent electrically actuated valvestherefor for independently actuating said pawl and ratchet feedingmechanisms, and an electrical interconnection including a switch betweensaid electrically actuated valves whereby the valves may operate eitherindependently or simultaneously.

17. In a crankpin grinding machine as claimed in claim 5, thecombination with the parts and features therein specified, .of a pair ofspaced steadyrests each having a frame and an adjustable shoesimultaneously to engage and steady a pair of spaced portions of a workpiece, slideways on said frames mating with correspondingly shapedslideways on said base, and connections between the steadyrest frames,and the grinding wheels whereby the steadyrests are indexedlongitudinally by and in timed relation with the longitudinal indexingmovement or the grinding wheels. r

18. In a grinding machine as claimed in claim 5, the combination withthe parts and features ward movement of the grinding wheels automati--caliy stops the work drive motor.

. RAYMOND A. COLE.

FRANKLIN E. JOHNSON.

